Sturgeon and Paddlefish Restoration Through Implementation of Fish Passage at the Prairie Du Sac Dam on the Wisconsin River

Two hundred years ago, lake sturgeon, shovelnose sturgeon, paddlefish, and blue sucker were found in the Wisconsin River from its confluence with the Mississippi River upstream to at least Wisconsin Dells at river kilometer 225. Completion of the 13-m Prairie du Sac Hydroelectric Dam at river kilometer 150 in 1914 fragmented the Wisconsin River, leading to the disappearance of shovelnose sturgeon, paddlefish, and blue sucker above the dam. Lake sturgeon still persist above the dam, but the population downstream of the dam has been cut off from the best spawning habitat in the river. In 2015, upstream and downstream fish passage facilities will become operational at the Prairie du Sac Dam, with the goal of restoring and reconnecting fish populations above and below the dam. The upstream passage facility will be a fish lift (i.e., elevator) designed specifically to accommodate large lake sturgeon and paddlefish. Fish using the facility will volitionally enter an approach channel and be guided into a hopper that will be lifted to a sorting area. Because of the threat of non-native invasives such as Asian carp using the lift, all fish will be identified at the sorting area, and only native species will be permitted to enter a flume that connects with the impoundment above the dam. The downstream passage facility will be a pipe and flume running through one of the turbine bays. Fish will enter the pipe volitionally and then be carried rapidly through the dam to the tailwater. Both facilities will operate throughout the open-water season, with a focus on the spring spawning migration from late March through early June and the fall migration to overwintering habitat from mid September through mid November. Detailed studies are planned to evaluate the effectiveness of the passage facilities in restoring sturgeon and paddlefish populations.